JP2001316442A - Manufacturing method of soft polyurethane molded foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily manufacture plural brands, especially plural groups of products, in a single production line. SOLUTION: The manufacturing method of a soft polyurethane molded foam comprises expansion using a polyol, a physical blowing agent and a polyisocyanate in a mold, where the apparent density of the soft polyurethane molded foam is controlled by varying the amount of the physical blowing agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a flexible polyurethane mold foam. Specifically, a method for producing a flexible polyurethane mold foam which is foamed in a mold using a polyol, a chemical foaming agent, a physical foaming agent, a catalyst, and if necessary, other auxiliaries and a polyisocyanate, comprising: The present invention relates to a method for producing a flexible polyurethane mold foam in which the apparent density of the flexible polyurethane mold foam is controlled by changing the amount.

[0002]

2. Description of the Related Art A flexible polyurethane mold foam (hereinafter sometimes abbreviated as a mold foam) has cushioning properties, so that it can be widely used in vehicles (eg, automobile seats, etc.), furniture (eg, bedding, etc.), miscellaneous goods and the like. It is used.

[0003] Different shapes and physical properties are required for each application such as a vehicle (for example, an automobile seat), furniture (for example, bedding), and miscellaneous goods. Furthermore, even for the same sheet or bedding, the shape, size,
Different product shapes and qualities such as density and vibration characteristics are required, and each end product forms a group. For example, in the case of automobile seats, the seat cushion has a shape that matches the buttocks and has a relatively high density and high rebound resilience, and the seat back that supports the back has a shape that is easy to hold the upper body from the back, for example, and has a relatively low density Is required. Also, the same seat cushion is frequently used, and a front cushion requiring high durability requires a higher density molded foam than a rear cushion. Due to the widespread use of small-lot, multi-product production and just-in-time production, it is necessary to reduce the stock of raw materials even at the manufacturing sites of automobile seats and bedding, etc. There is an increasing need to manufacture and deliver these parts as a set.

[0004] This mold foam comprises a polyol, a polymer polyol in which polymer particles are dispersed in a polyol obtained by radical polymerization of acrylonitrile or styrene in the polyol, water as a chemical foaming agent, a silicone-based surfactant, an amine or the like. It is produced by mixing a catalyst such as tin or a tin compound, a crosslinking agent or the like, if necessary, a flame retardant, a pigment or the like, and a polyisocyanate. Water as a chemical foaming agent reacts with the polyisocyanate, and the desorbed carbon dioxide gas becomes a foaming gas, and at the same time, functions as a foaming agent by a reaction of generating polyurea.

In general, a polyol, a polymer polyol in which polymer particles are dispersed in a polyol obtained by radical polymerization of acrylonitrile or styrene in the polyol, water as a chemical foaming agent, a silicone-based surfactant, a catalyst, If necessary, a crosslinking agent or the like is treated as a resin premix mixed in advance. Conventionally, when producing multiple brands of products having different apparent densities, it is necessary to change the resin premix composition such as the number of water parts as a chemical foaming agent for each product. It was necessary to prepare a plurality of storage tanks.

Also, a method of changing the amount of raw material injected into a mold (the minimum weight of a mold foam required to obtain a shape corresponding to the mold with a specific mold is called a just pack, and the It is also conceivable that injection molding of an excessive amount is called an overpack), but molding defects such as so-called sink marks are apt to occur near the just pack, and when the overpack ratio is high, the strength of the cell at the time of demolding is too high. The workability of crushing for mechanically connecting the cells is reduced, the mold foam is ruptured during crushing (crushing crack), and the mold foam is liable to shrink.

Although the workability is low, it is possible to form a mold foam under the condition of a high overpack rate by selecting the crushing conditions. However, in the case of a mold having a complicated shape, the selection range of the overpack ratio that can be practically formed is in the range of 15% to 75%. For example, a resin preform having an apparent density of 32 kg / m ³ at the time of just pack is used. The molding density width when using the mix and the polyisocyanate ranges from 37 kg / m ³ to 56 kg / m ³ . Therefore, that the apparent density is produced without changing the combination of both the resin premix and polyisocyanate seatback molded foam of 55 kg / m front cushion mold form ³ and apparent density of 33 kg / m ³ could not.

[0008] With the demand for diversification of mold foam items and cost reduction, a method for producing a flexible polyurethane foam of another kind without changing the combination of resin premix and polyisocyanate has been desired.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for easily and inexpensively producing a set of mold foam products suitable for small-quantity multi-products and just-in-time.

[0010]

The present inventors have made various studies.
As a result, by changing the amount of the physical blowing agent, various
Finding that mold foam can be manufactured efficiently
The present invention has been completed. That is, the present invention provides the following (1) to
(5) is provided. (1) Polyols, physical blowing agents and polyisocyanates
Soft polyurethane mold foamed in a mold using
A method for producing a foam, wherein the amount of the physical blowing agent is changed.
Flexible polyurethane mold foam
Flexible polyurethane mold for controlling the apparent density of
Method of manufacturing the game. (2) The polyol described in (1) is at least polyoxy
Soft using polyol containing alkylene polyol
For producing high quality polyurethane molded foam. (3) 100 parts by weight of polyol
Soft by controlling the discharge amount within 3 parts by weight
Control the apparent density of polyurethane molded foam
The flexible polyurethane mold foam described in (1) or (2)
Method of manufacturing the game. (4) Changing the discharge amount of the physical foaming agent to the mold
Of the resulting flexible polyurethane mold foam
25kg / m apparent density^ThreeOr 45kg / m^ThreeOr 35kg / m ^ThreeAbsent
65 kg / m^Three(1) No control
(3) The flexible polyurethane mold mold described in (3)
Manufacturing method. (5) Simultaneously with changing the amount of physical foaming agent discharged to the mold
Resin premix containing polyol and poly
Filling amount of the mixture of the cyanate into the mold, NC of the mixture
By changing at least one of the O-index
To increase the apparent density of the flexible polyurethane mold foam.
30kg / m^ThreeOr 60kg / m^Three, Hardness 80N / 314cm^TwoOr 500N / 3
14cm^TwoThe soft poly according to (1) to (3), which is controlled in the range of
Manufacturing method of urethane mold foam.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The method for producing a flexible polyurethane mold foam of the present invention is a flexible polyurethane foam which is foamed in a mold using a polyisocyanate, a physical foaming agent, a polyol and, if necessary, a chemical foaming agent, a catalyst and other auxiliaries. A method for producing a polyurethane mold foam, wherein the apparent density of a flexible polyurethane mold foam is controlled by changing the discharge amount of the physical foaming agent into a mold. In the present invention, unless otherwise specified, parts and%
Means parts by weight and mass%, respectively. Hereinafter, first, each component used in producing the flexible polyurethane mold foam will be described.

[Polyol] In the present invention, examples of the polyol to be reacted with the polyisocyanate compound include polyhydric alcohols such as divalent to hexavalent, polyoxyalkylene polyols, polyester polyols and polymer polyols. In particular, it is preferable to use polyoxyalkylene polyol, polyester polyol,
More preferably, a polyoxyalkylene polyol is used. These polyols may be used alone or in combination of two or more.

The hydroxyl value of the polyol is 15 mgKOH / g or more and 60 m
gKOH / g or less, preferably 15 mgKOH / g or more and 45 mgKOH / g or less, more preferably 20 mgKOH / g or more and 35 mgKOH / g or less.

As the polyol, 0.5 to 30 parts of a polyol having an ethylene oxide content in the alkylene oxide of 20% by mass or more and a hydroxyl value of 15 mgKOH / g to 100 mgKOH / g can be used.

<Polyhydric alcohol> Polyhydric alcohols used in the present invention include, for example, dihydric alcohols such as ethylene glycol and propylene glycol, and trihydric alcohols such as glycerin and trimethylolpropane.
Examples of the polyhydric alcohol include pentaerythritol and diglycerin, and examples of the hexahydric alcohol include sorbitol.

<Polyoxyalkylene polyol> The polyoxyalkylene polyol refers to an oligomer or polymer obtained by ring-opening polymerization of an alkylene oxide, and is usually used in the presence of a catalyst to activate an alkylene oxide using an active hydrogen compound as an initiator. Obtained by ring polymerization. These may be used alone or in combination. Sometimes referred to as polyoxyalkylene polyether polyol. In producing the polyoxyalkylene polyol, the initiator and the alkylene oxide may be used alone or in combination.

The polyoxyalkylene polyol according to the present invention has a hydroxyl value of 15 mgKOH / g to 60 mgKOH / g, preferably a hydroxyl value of 15 mgKOH / g to 45 mgKOH / g, and more preferably a hydroxyl value of 20 mgKOH / g to 35 mgKOH / g. g or less. It goes without saying that these polyoxyalkylene polyols may be used alone or in combination of two or more.

The moldability and cure properties of the mold foam,
When the mechanical properties are further enhanced, the terminal oxyethylene group content is preferably 5% by mass or more and 30% by mass or less, and more preferably 10% by mass or more and 25% by mass or less.

<Active hydrogen compound for producing polyoxyalkylene polyol> Examples of the active hydrogen compound used as an initiator in producing a polyoxyalkylene polyol include an active hydrogen compound having an active hydrogen atom on an oxygen atom and an active hydrogen compound on a nitrogen atom. An active hydrogen compound having an atom is exemplified.

Among the active hydrogen compounds in the method of the present invention, the active hydrogen compound having an active hydrogen atom on an oxygen atom includes water, a carboxylic acid having 1 to 20 carbon atoms, and a carboxyl having 2 to 6 carbon atoms having 2 to 20 carbon atoms. Polyhydric carboxylic acids having a group, carbamic acids, alcohols having 1 to 20 carbon atoms, polyhydric alcohols having 2 to 8 hydroxyl groups having 2 to 8 carbon atoms, saccharides or derivatives thereof, and 1 to 6 carbon atoms Aromatic compounds having 1 to 3 hydroxyl groups, polyalkylene oxides having 2 to 8 terminals and having 1 to 8 hydroxyl groups at the terminals, and the like.

As the carboxylic acid having 1 to 20 carbon atoms,
For example, formic acid, acetic acid, propionic acid, isobutyric acid, lauric acid, stearic acid, oleic acid, phenylacetic acid, dihydrocinnamic acid or cyclohexanecarboxylic acid, benzoic acid,
Examples include paramethylbenzoic acid or 2-carboxyhydrophthalenic acid.

Examples of the polyvalent carboxylic acids having 2 to 6 carboxyl groups having 2 to 20 carbon atoms include oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, adipic acid, itaconic acid, butanetetracarboxylic acid and phthalic acid acid,
Examples include isophthalic acid, terephthalic acid, trimellitic acid, and pyromellitic acid.

Examples of the carbamic acids include N, N-diethylcarbamic acid, N-carboxypyrrolidone, N-carboxyaniline, N, N-dicarboxy-2,4-toluenediamine and the like.

Examples of the alcohol having 1 to 20 carbon atoms include methanol, ethanol, normal-propanol, iso-propanol, normal-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol,
Iso-pentyl alcohol, tert-pentyl alcohol,
Normal-octyl alcohol, lauryl alcohol,
Cetyl alcohol, cyclopentanol, cyclohexanol, allyl alcohol, crotyl alcohol, methylvinylcarbinol, benzyl alcohol, 1-phenylethyl alcohol, triphenylcarbinol, cinnamyl alcohol and the like can be mentioned.

Examples of the polyhydric alcohol having 2 to 8 hydroxyl groups having 2 to 20 carbon atoms include ethylene glycol, propylene glycol, diethylene glycol,
Dipropylene glycol, 1,3-propanediol, 1,3-
Butanediol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanediol, trimethylolpropane, glycerin, diglycerin, pentaerythritol or dipentaerythritol.

Examples of the saccharide or a derivative thereof include glucose, sorbitol, dextrose, fructose and sucrose. 6 to 2 carbon atoms
Examples of the aromatic compounds having 0 to 1 hydroxyl group include phenol, 2-naphthol, 2,6-dihydroxynaphthalene, bisphenol A and the like. Examples of polyalkylene oxides having 1 to 8 hydroxyl groups at the terminal include polyethylene oxide, polypropylene oxide, and copolymers thereof.

Among the active hydrogen compounds in the method of the present invention, the active hydrogen compounds having an active hydrogen atom on a nitrogen atom include aliphatic or aromatic primary amines having 1 to 20 carbon atoms and 2 to 20 carbon atoms. Aliphatic or aromatic secondary amines, polyvalent amines having 2 to 3 primary or secondary amino groups having 2 to 20 carbon atoms, saturated cyclic secondary amines having 4 to 20 carbon atoms, carbon number Unsaturated cyclic secondary amines having 4 to 20 carbon atoms, cyclic polyvalent amines having 2 to 3 secondary amino groups having 4 to 20 carbon atoms, unsubstituted or N-monosubstituted acids having 2 to 20 carbon atoms Examples include amides, 5- to 7-membered cyclic amides, and imides of dicarboxylic acids having 4 to 10 carbon atoms.

Examples of the aliphatic or aromatic primary amines having 1 to 20 carbon atoms include methylamine, ethylamine, normal-propylamine, isopropylamine, and the like.
Examples include normal-butylamine, isobutylamine, sec-butylamine, tert-butylamine, cyclohexylamine, benzylamine, β-phenylethylamine, aniline, o-toluidine, m-toluidine, p-toluidine and the like.

Examples of the aliphatic or aromatic secondary amines having 2 to 20 carbon atoms include dimethylamine, methylethylamine, diethylamine, di-normal-propylamine, ethyl-normal-butylamine, methyl-sec-butylamine, dipentyl. Examples include amine, dicyclohexylamine, n-methylaniline, diphenylamine, and the like. Examples of polyvalent amines having 2 to 3 primary or secondary amino groups having 2 to 20 carbon atoms include ethylenediamine, di (2-aminoethyl) amine, hexamethylenediamine, 4,4'-diaminodiphenylmethane, triamine, and the like. (2-aminoethyl) amine, N, N'-dimethylethylenediamine, N, N'-diethylethylenediamine or di (2
-Methylaminoethyl) amine and the like.

Examples of the saturated cyclic secondary amine having 4 to 20 carbon atoms include pyrrolidine, piperidine, morpholine and 1,2,3,4-tetrahydroquinoline.

Examples of the unsaturated cyclic secondary amine having 4 to 20 carbon atoms include 3-pyrroline, pyrrole, indole, carbazole, imidazole, pyrazole and purine.

Examples of the cyclic polyvalent amines having a C2 to C2 and C2 to C3 secondary amino group include piperazine, pyrazine and 1,4,7-triazacyclononane.

Examples of the unsubstituted or N-monosubstituted acid amides having 2 to 20 carbon atoms include acetamido, propionamide, N-methylpropionamide, N-methylbenzoic amide and N-ethylstearic amide. No.

Examples of the 5- to 7-membered cyclic amide include 2-pyrrolidone and ε-caprolactam.

The imides of dicarboxylic acids having 4 to 10 carbon atoms include, for example, succinimide, maleic imide and phthalimide.

Of these active hydrogen compounds, preferred is water, for example, methanol, ethanol, normal-propanol, isopropanol, normal-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isopentyl alcohol, tert-butyl alcohol. Pentyl alcohol, normal-octyl alcohol, lauryl alcohol, cetyl alcohol, cyclopentanol, cyclohexanol, allyl alcohol, crotyl alcohol, methyl vinyl carbinol, benzyl alcohol,
C1-C20 alcohols such as 1-phenylethyl alcohol, triphenylcarbinol or cinnamyl alcohol; ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,3-propanediol, 1,3- Butanediol,
Hydroxy groups having 2 to 20 carbon atoms having 2 to 20 carbon atoms such as 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanediol, trimethylolpropane, glycerin, diglycerin, pentaerythritol or dipentaerythritol Polyhydric alcohols having glucose,
A saccharide such as sorbitol, dextrose, fructose or sucrose or a derivative thereof, for example, a polyalkylene oxide having a molecular weight of 100 to 50,000 and having a terminal 1 to 8 hydroxyl group such as polyethylene oxide, polypropylene oxide or a copolymer thereof; Yes, ethylenediamine, di (2-aminoethyl)
Amine, hexamethylenediamine, 4,4'-diaminodiphenylmethane, tri (2-aminoethyl) amine, N, N'-
Polyamines having 2 to 3 carbon atoms and having 2 to 3 primary or secondary amino groups such as dimethylethylenediamine, N, N'-diethylethylenediamine or di (2-methylaminoethyl) amine; pyrrolidine, piperidine A saturated cyclic secondary amine having 4 to 20 carbon atoms such as morpholine or 1,2,3,4-tetrahydroquinoline, and having 4 to 20 carbon atoms such as piperazine, pyrazine or 1,4,7-triazacyclononane. Cyclic polyvalent amines containing 20 secondary or 3 secondary amino groups. More preferably, it is water, for example, methanol, ethanol, normal-propanol, isopropanol, normal-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol,
C 1 -C such as isopentyl alcohol, tert-pentyl alcohol or normal-octyl alcohol
10 alcohols, having 2 to 10 C 2 to 4 hydroxyl groups such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, trimethylolpropane, glycerin or pentaerythritol Polyhydric alcohols, such as polyethylene oxide, polypropylene oxide or copolymers thereof, having 2 to 6 terminals and having 2 to 6 hydroxyl groups at the terminals and having a molecular weight of 100 to 10,000 Polyvalent amines having 2 to 10 carbon atoms and having 2 to 3 carbon atoms, such as N, N'-dimethylethylenediamine, N, N'-diethylethylenediamine or di (2-methylaminoethyl) amine; And pyrrolidine, piperidine, morpholine or 1,2,3,4-tetra C4 to C10 saturated cyclic secondary amines such as hydroquinoline, and include C4 to C2 secondary amino groups such as piperazine, pyrazine or 1,4,7-triazacyclononane. And cyclic polyamines.

(Alkylene oxide compound) As the alkylene oxide compound used for producing the polyoxyalkylene polyol of the present invention, ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-
Butylene oxide, styrene oxide, cyclohexene oxide, epichlorohydrin, epibromohydrin,
Epoxy compounds such as methyl glycidyl ether, allyl glycidyl ether and phenyl glycidyl ether. Among these alkylene oxide compounds, ethylene oxide, propylene oxide, 1,2-butylene oxide or styrene oxide is preferred, and ethylene oxide and propylene oxide are more preferred.

These may be used in combination of two or more. When used in combination, a method of simultaneously using a plurality of alkylene oxide compounds, a method of sequentially using a plurality of alkylene oxide compounds, or a method of repeatedly repeating the steps can be employed.

When used in combination, it is particularly preferable that the ratio of ethylene oxide in the alkylene oxide is 5 to 30% by mass.

<Polymer polyol> In the present invention,
A polymer-dispersed polyol (hereinafter sometimes referred to as a polymer polyol) is a compound having an unsaturated bond such as acrylonitrile or styrene dispersed and polymerized in a polyol using a radical initiator such as azobisisobutyronitrile. Vinyl polymer particles containing the obtained partially grafted product (hereinafter sometimes simply referred to as polymer fine particles)
Say dispersion.

The polyol used here may be any of the aforementioned polyols, but it is more preferable to use a polyoxyalkylene polyol. The polymer obtained by this dispersion polymerization generally has an average particle size of 0.1 to 1
0 micrometers.

In the polymer-dispersed polyol used in the present invention, the proportion of the fine polymer particles in the polyoxyalkylene polyol is usually 2 to 50% by mass, preferably 10 to 40% by mass.

(Compound Having an Unsaturated Bond) The compound having an unsaturated bond is a compound having an unsaturated bond in the molecule, for example, acrylonitrile, styrene and the like. These can be used alone or in combination of two or more. In addition, a dispersion stabilizer, a chain transfer agent and the like may be used in combination.

[Polyisocyanate] The polyisocyanate to be reacted with the polyol is not particularly limited, but the conventionally known tolylene diisocyanate (the isomer ratio such as 2,4-form or 2,6-form is not particularly limited. 4-body / 2,6-body 80/20
The ratio is preferably used. ) Or a mixture of tolylene diisocyanate and polymethylene polyphenyl polyisocyanate (for example, Cosmonate M-200 manufactured by Mitsui Chemicals, Inc.) is preferably used. When the polyisocyanate is a mixture of tolylene diisocyanate and polymethylene polyphenyl polyisocyanate, a mixing ratio of 98: 2 to 50:50 by weight is particularly suitable for producing a flexible polyurethane foam.

A mixture of polyisocyanate, which is a composition of polymethylene polyphenyl polyisocyanate, or a urethane modified product thereof and tolylene diisocyanate can also be preferably used.

The total number of isocyanate groups in the polyisocyanate is determined by determining the hydroxyl groups of the polyol, amino groups such as a crosslinking agent,
The value divided by the total number of active hydrogens that react with isocyanate groups such as water is defined as the NCO index. That is, when the number of active hydrogens that react with isocyanate groups and the isocyanate groups in the polyisocyanate are stoichiometrically equal, the NCO
The index is 1.0. The NCO index in the present invention ranges from 0.6 to 1.5, preferably 0.8 to 1.3.

[Physical foaming agents] As physical foaming agents, chlorofluorocarbons developed for the purpose of protecting the global environment,
Hydroxychlorofluorocarbons (HCFC-134a
Etc.), hydrocarbons (such as cyclopentane), carbon dioxide gas, liquefied carbon dioxide gas, and other blowing agents are used alone or in combination with water as a foaming aid.
From the viewpoint that the density of the flexible polyurethane mold foam can be largely changed by changing the addition amount in a small amount, carbon dioxide and liquefied carbon dioxide are preferred, and liquefied carbon dioxide is more preferred. When the amount is 3 parts by weight or less with respect to 100 parts by weight of the polyol, foaming is stable and preferable, and the amount is more preferably 2.5 parts by weight or less.

[Urethane Foam Foaming Aid] The auxiliary agent used for urethane foaming includes a crosslinking agent, a foam stabilizer, a catalyst for producing polyurethane foam, a chemical foaming agent, etc., each of which can be added as needed. Needless to say, other additives and the like may be used in combination.

(Crosslinking Agent) The crosslinking agent need not be particularly used, but when it is used, a compound having a hydroxyl value of 200 to 1800 mgKOH / g is used.

Examples of such a crosslinking agent include aliphatic polyhydric alcohols such as glycerin, diethanolamine,
Alkanolamines such as triethanolamine, polyoxyalkylene polyols and the like are used. Others
Conventionally known crosslinking agents may be used, and these may be used alone or in combination of two or more.

The crosslinking agent is used in an amount of 0.5 to 100 parts by weight of the polyol.
Any amount can be used between parts and 10 parts.

(Foam stabilizer) As the foam stabilizer, an organosilicon-based surfactant usually used for producing a polyurethane foam can be used. The amount used is 0.2 parts to 100 parts by weight of the polyol.
3 parts, for example, SRX-274C, SF-2969, SF-2961, SF-2962 manufactured by Dow Corning Toray Silicone Co., Ltd. and L-5309, L-3601, L-5307, L-307 manufactured by Nippon Unicar 3600 etc. can be used.

(Catalyst Used for Production of Flexible Polyurethane Mold Foam) As a catalyst used for production of a flexible polyurethane mold foam, a conventionally known catalyst can be used.

The catalyst is not particularly limited, but includes, for example, aliphatic amines such as triethylenediamine, bis (N, N-dimethylaminoethylether), morpholines, and organic tin compounds such as tin octoate and dibutyltin dilaurate. Is mentioned. These catalysts may be used alone or in combination. The amount used is 0.005 per 100 parts by weight of polyol
It is preferred to use from 1 to 10 parts.

(Chemical blowing agent) Water is used as a chemical blowing agent by reacting with polyisocyanate to generate carbon dioxide gas.

The amount usually used is preferably 1 part to 7 parts, more preferably 2.5 parts to 6 parts, per 100 parts by weight of the polyol.

[Production Method of Flexible Polyurethane Mold Foam] A flexible polyurethane mold foam is produced by foaming in a mold using a polyol, a polyisocyanate, a physical foaming agent and other components as required. Other components, for example, chemical blowing agents,
It is manufactured by foaming in a mold using a cross-linking agent, a surfactant, a catalyst, a foam stabilizer, and other additives (a flame retardant, a pigment, an ultraviolet absorber, an antioxidant, and the like).

It is preferable that the polyisocyanate and the polyol are mixed immediately before foaming. The other components are generally preliminarily mixed with a polyisocyanate or a polyol in advance, if necessary. The mixture may be used immediately after mixing, or may be stored and used in an appropriate amount. As for the mixing of other components, the combination of the mixing, the mixing order, the storage time after the mixing, and the like can be determined as appropriate.

[0059] Among such mixtures, a mixture of a polyol and other components is sometimes referred to as a resin premix. The viscosity of the resin premix used is 2500 mPa · s / ° C from the viewpoint of mixability with a foaming machine and foam moldability.
The following is preferred. The resin premix is usually a mixture of a polyol, a chemical foaming agent, a catalyst, and the like, if necessary, a crosslinking agent, a surfactant, a catalyst, a foam stabilizer, and other additives, and is reacted with the polyisocyanate. The composition is appropriately changed depending on the required quality of the flexible polyurethane mold foam.

The mixing method may be either dynamic mixing for mixing in a machine head mixing chamber of a foaming machine, or static mixing for mixing in a liquid feed pipe, or both may be used in combination. Mixing performed immediately before foaming or mixing of a gaseous component and a liquid component such as a physical foaming agent is performed by static mixing, and mixing of storable components is often performed by dynamic mixing. The mixing temperature and pressure can be arbitrarily set as required according to the quality of the intended flexible polyurethane mold foam, the type and composition of the raw materials.

The production method of the present invention is a method for producing a flexible polyurethane mold foam using a physical foaming agent, and is a method for controlling the apparent density of the flexible polyurethane mold foam by changing the amount of the physical foaming agent. In particular, the present invention provides a method suitable for producing a mold foam having an apparent density of 25 kg / m ³ to 45 kg / m ³ or 35 kg / m ³ to 65 kg / m ³ . In addition, by changing the filling amount into the mold and the NCO index, the apparent density of the flexible polyurethane mold foam is 30 kg / m ³ to 60 kg /
The present invention also provides a method suitable for producing a mold foam having a m ³ and a hardness in the range of 80 N / 314 cm ² to 500 N / 314 cm ² without changing the combination of the resin premix and the polyisocyanate.

In the present invention, any method and combination of apparatuses can be used as long as the apparent density of the flexible polyurethane mold foam can be controlled by changing the amount of the physical foaming agent. An example is shown below. Needless to say, the present invention is not limited to the following description.

An embodiment of the present invention will be described with reference to the schematic diagram (FIG. 1) of the manufacturing process flow of the cold cure mold foam. A resin premix in which a polyol, a catalyst, a chemical foaming agent, a foam stabilizer, and a crosslinking agent are mixed in advance and a physical foaming agent are mixed with a line mixer (for example, a static mixer).
13 is a cold cure mold foam production facility for mixing with polyisocyanate and subsequently mixing with a mixing head 9 and injecting and foaming into a mold. In this apparatus, the apparent density of the product is controlled by changing the amount of the physical foaming agent by the physical foaming agent metering pump 11.

The polyisocyanate is stored in the polyisocyanate storage tank 1 and supplied to the mixing head 9 via the polyisocyanate outward pipe 5 by the polyisocyanate metering pump 3 to be mixed with the mixture of the resin premix and the physical foaming agent. You. At times other than discharge, the polyisocyanate supplied via the outgoing pipe 5 is circulated to the polyisocyanate storage tank 1 via the polyisocyanate return pipe 6.

The above-mentioned resin premix is stored in a resin premix storage tank, supplied to the line mixer 13 as a static mixer via the resin premix outgoing pipe 7 by the resin premix metering pump 4, and supplied to the line mixer 13 as a physical foaming agent. Is supplied to the mixing head 9 and mixed with the polyisocyanate. At times other than discharge, the resin premix supplied through the outgoing pipe 7 is circulated through the resin premix return pipe 8 to the resin premix storage tank 2.

The physical foaming agent is supplied from the physical foaming agent container 10 to the line mixer 13 by the physical foaming agent metering pump 11 through the physical foaming agent liquid sending pipe 12 and mixed with the resin premix. And mixed with the polyisocyanate. The physical foaming agent may be mixed with the resin premix by the line mixer in the vicinity of the mixing head as described above, but the line mixer is installed on the outgoing pipe side for the polyisocyanate, mixed with the physical foaming agent and the polyisocyanate, and supplied to the mixing head. Alternatively, the three may be directly mixed by a mixing head.

The amounts of the resin premix, polyisocyanate and physical foaming agent can be independently changed for each shot with respect to other components. The amount of physical foaming agent used may be zero depending on the required quality of the target product.

In the mixing head 9, a mixture of the resin premix and the physical foaming agent and the polyisocyanate are mixed to form a foaming stock solution. Frothing liquid is injected into the mold a _2. In the mixing head, two or more liquids may be supplied and mixed, and the raw material liquids such as polyol type, chemical blowing agent type, catalyst type, flame retardant type, polyisocyanate type, and physical blowing agent type are divided into respective series. To the mixing head 9 to adjust the foaming stock solution.

In particular, when a hydrolyzable compound such as an organotin catalyst is used as a catalyst, a water component or an organotin catalyst component is directly supplied to the mixing head as a separate system to avoid contact with water and mixed. Is preferred.

The adjusted foaming undiluted solution is mixed with the mixing head 9.
Into a mold and foamed, filled, and cured to obtain a target having a uniform shape. The apparent density of the mold foam can be controlled by the total amount of the physical blowing agent used.

During foaming and curing, the temperature is usually maintained at a predetermined temperature. After curing is completed, the mold is opened. After demolding, the molded product is crushed as necessary to produce a product. The mold is cleaned and a release agent is applied. It is then used for molding the next product.

The production of the mold foam may be carried out with a single die, but usually, a plurality of dies, for example, a ₀ to
The mold of a _n arranged on top of the belt conveyor or turntable, to perform the molding is usually carried out while successively using it. Specifically, a mold (a ₀ ~a _n) are provided arranged sequentially on a conveyor 16 of the working zone 14 and the curing oven 15, the application of the release agent in the working sone 14, injection of the stock solution, demoulding The foaming and curing are performed while maintaining a predetermined temperature in a curing oven. An example of each process in a work zone is shown. For example
At a ₀ , a release agent is applied using a spray 17,
is set insert material in a _1, injected undiluted injection and physical blowing agent in a _2, after being closed in a _3, sent to the curing oven 15.

The curing oven 15 is maintained at a predetermined temperature, and the foam molding and the curing reaction are completed in the oven. Although the temperature inside the oven may be the same, the inside of the oven may be divided into a plurality of sections, and the temperature may be changed for each section and controlled. When the curing reaction is completed, the mold is sent from the oven to the working zone 14. and-open type in a _n-2, the product 18 in a _n-1 is released from the mold, cleaning of the mold is made in a _n. In the demolded product, all closed cells remaining in the product in the crushing step (not shown) are made into continuous cells, and post cure is performed as necessary.

The curing time is usually from 30 seconds to 30 minutes, the mold temperature is from room temperature to about 80 ° C., and the curing temperature is from room temperature to 180 ° C. It is also possible to use a method of controlling the mold temperature by using a jacket provided on a mold without using a curing oven. Although described without particularly distinguishing a ₀ ~a _n for convenience in this description,
In order to manufacture different products in one line, or in some cases, different product groups, some or all of the molds may have different product physical properties, product shapes, and the like.

When these different molds are used, it is possible to arbitrarily set how many kinds of mold groups and how many cycles are to be installed on the same line. When using an existing production line, it is determined according to the capacity of the existing equipment. Particularly, by changing the amount of the physical blowing agent, a urethane mold foam having a wide range of apparent density can be produced even with the same polyisocyanate and resin premix. If necessary, the amount of the release agent, the presence or absence of the insert material, and the type can be appropriately changed according to the product to be manufactured in each mold. The amount of the physical foaming agent can be set according to the physical properties of each product and the raw material composition such as polyisocyanate and polyol used, and may be manually controlled in accordance with each mold. If measures are taken, automatic control can be achieved.

Hereinafter, the automatic control method will be described with reference to FIG. FIG. 2 is a block diagram showing the configuration of the control device for the physical foaming agent. Mold type detecting means 101 for detecting the mold type from the mold type discriminating means, resin premix composition detecting means 102 for detecting the resin premix composition in the resin premix storage tank 2, and polyisocyanate in the polyisocyanate storage tank 1. It has a polyisocyanate composition detecting means 103 for detecting the composition, and transmits a detection result obtained by each detecting means to the physical foaming agent calculating means 104.

The physical foaming agent data calculation means is input in advance with a map of the discharge amount of each raw material and physical foaming agent corresponding to each mold type and raw material composition. The physical foaming agent data calculating means calculates the discharge amount of each raw material and the physical foaming agent corresponding to each mold from the detection result according to the map, the resin premix discharge amount adjusting means 105, the isocyanate discharge amount adjusting means 106, A control signal is output to each of the physical foaming agent discharge amount adjusting means 107. Each control means controls each discharge means based on the control signal. For example, the resin premix discharge amount adjusting means 105 controls the rotation speed of the resin premix metering pump. As described above, the discharge amount of the resin premix, the discharge amount of the isocyanate, and the physical blowing agent may all be changed in accordance with the mold type, but a mold selected by substantially changing only the physical blowing agent may be used. It is possible to control the apparent density of the foam over a wide range. Therefore, it is sufficient to create a map of the discharge amount of each raw material and physical foaming agent corresponding to each mold type and raw material composition by using the physical foaming agent as a main control factor. Good.

Further, since the physical properties and shape of the mold foam can be controlled over a wide range without changing the composition of the resin premix or polyisocyanate, the composition of each composition is input to the calculation means in advance, regardless of the detection means. Based on this, the required physical foaming agent discharge amount is calculated, and control can be performed by outputting a control signal.

The mold type judging means can judge a use and a use portion of a product manufactured by the mold. For example, a recognition means is provided so that the brand number can be determined. This recognition means may be given any classification as long as it can identify the product, and the recognition means may be directly described by a single code or a combination of a plurality of numbers, alphabets, kanji, etc. You may. It should be noted that the mold type and each product are associated one-to-one in this map, and it is necessary to classify them as different mold types when creating different products even if the molds have the same shape.

[Action] Since the apparent density of the mold foam obtained by substantially changing only the physical foaming agent can be controlled in a wide range, a plurality of brands, particularly a plurality of product groups, can be obtained on a single line. Can be easily manufactured. As a result, parts required for one product can be manufactured in one cycle at a time even in automobile seats, beddings, and the like having different required shapes and performances for different parts of use. In addition, since the manufacturing order can be arbitrarily set in the order of the molds, each part can be manufactured in an order suitable for the shipping form of the product, particularly, packing at the time of shipping.

For example, when manufacturing a set for an automobile seat, two molds for a front seat cushion, two molds for a rear seat cushion, and two molds for a rear seat back can be sequentially arranged and manufactured as one cycle. It is not always necessary to repeat the same cycle. For example, a set of sports car type cars, a set of van type cars, a set of land vehicle type cars, etc. may be sequentially arranged. The arrangement of the dies can be arbitrarily determined according to the required products and work efficiency. Naturally, a completely different product group, for example, an automobile seat set and a bedding set can be simultaneously manufactured on the same line. .

[Physical Properties and Uses of Flexible Polyurethane Mold Foam] The apparent density of the flexible polyurethane molded foam to be produced is not particularly limited. However, when the apparent density is controlled by controlling only the physical foaming agent, 35 kg / m ³ to 65 kg. It is preferable to control the pressure in the range of 25 kg / m ³ or 25 kg / m ³ to 45 kg / m ³ . The use is not particularly limited, but if exemplified in a mold foam application for an automobile sheet,
In the former range, mold foam for front seat cushion and mold foam for rear seat cushion,
The latter range is suitable for a mold foam for a rear seat cushion and a mold foam for a seat back.

When the apparent density is controlled by controlling the physical foaming agent and the filling amount (overpack ratio) in the mold, it is preferable to control the apparent density in the range of 30 kg / m ³ to 60 kg / m ³ . At this time, it is preferable to control the NCO index of the mixture of the resin premix and the polyisocyanate together.

(Measurement Method) Apparent density: Measurement was carried out according to the method described in JIS K-6400. Refers to the apparent density in the JIS standard. In this patent, 100 × 100 × 50mm from the core of rectangular parallelepiped foam with skin skin
Was cut out and measured.

Hardness of mold foam: A of JIS K-6400
The measurement was performed by the method described in the method. Foam thickness 94
mm to 100 mm was used. In this patent, measurement was performed using a rectangular foam sample having a skin skin.

Tensile strength, elongation and tear strength: JIS K-64
The measurement was carried out according to the method described in Example 00.

Hydroxyl value: Measured according to the method described in JIS K-1557.

[0088]

EXAMPLES Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. Parts and% in the examples represent parts by weight and% by mass, respectively. In this example, the following raw materials were used.

(Polyoxyalkylene polyol A) A polyoxyalkylene polyol having a chain end oxyethylene group content of 15% and a hydroxyl value of 34 mgKOH / g obtained by ring-opening polymerization of propylene oxide and ethylene oxide with an active hydrogen compound having 3 functional groups. (Polyoxyalkylene polyol B) A chain-end oxyethylene group content of 15 obtained by ring-opening polymerization of propylene oxide and ethylene oxide with an active hydrogen compound having 4 functional groups.
%, Polyoxyalkylene polyol having a hydroxyl value of 34 mgKOH / g. (Polyoxyalkylene polyol C) A chain-end oxyethylene group content of 15 obtained by subjecting an active hydrogen compound having 4 functional groups to ring-opening polymerization of propylene oxide and ethylene oxide.
%, A polyoxyalkylene polyol having a hydroxyl value of 28 mgKOH / g. (Polymer polyol D) A polymer polyol having a hydroxyl value of 27 mgKOH / g obtained by graft-polymerizing 20 parts of acrylonitrile to 100 parts of polyoxyalkylene polyol A. (Polymer polyol E) A polymer polyol having a hydroxyl value of 23 mgKOH / g obtained by graft-polymerizing 20 parts of acrylonitrile to 100 parts of polyoxyalkylene polyol C. (Polymer polyol F) A hydroxyl value of 27 m obtained by graft-polymerizing 16 parts of acrylonitrile and 4 parts of sterene to 100 parts of polyoxyalkylene polyol A
gKOH / g polymer polyol. (Water) Ion-exchanged water (Crosslinking agent) KL-210; Polyol (Catalyst-1) manufactured by Mitsui Chemicals, Inc. Minico L-1020; Amine-based catalyst manufactured by Active Materials Chemical Co. (33% diethylene glycol solution of triethylenediamine) (Catalyst- 2) Minico TMDA; 70% of amine-based catalyst (bis (dimethylaminoethyl) ether manufactured by Active Materials Chemical Co., Ltd.)
(Dipropylene glycol solution) (Foam stabilizer-1) L-3601; Nippon Unicar company foam stabilizer (Foam stabilizer-2) L-5309; Nippon Unicar company foam stabilizer (polyoxyalkylene polyol G) EP-505S; Mitsui Chemicals Polyol (Isocyanate H) Polymethylene polyphenyl polyisocyanate-based isocyanate obtained by subjecting 13% of tolylene diisocyanate and 75% of polymethylene polyphenyl polyisocyanate to urethane modification with 16% of polyoxyalkylene polyol . (Isocyanate I) Cosmonate TM-20; Isocyanate manufactured by Mitsui Chemicals, Inc. (Preparation of resin premix) A resin premix was prepared according to the following formulation.

(Example 1) Polyoxyalkylene polyol and polymer polyol as described in Table 1, 3.6 parts of water, 0.4 parts of catalyst-1, and catalyst-2
0.05 part and 1 part of foam stabilizer-1 were mixed to prepare a resin premix. The resin premix and the polyisocyanate were mixed and discharged using a high-pressure foaming machine, and injected into a mold to prepare a molded foam molded article for foam evaluation. At this time, the amount of the polyisocyanate was adjusted so that the NCO index of the resin premix and the polyisocyanate to be injected into the mold was 1.00.

Mold: 400 × 400 × 100 mm aluminum test mold Mold temperature: 56 to 60 ° C. Six minutes after injection of the molded foam, crushing was performed. Crushing 50m of molded product
This was done by passing through a m-width and then a 20 mm-width rotary roller.

The amount of carbon dioxide used was 0 parts (not used) and 2 parts based on 100 parts of the polyoxyalkylene polyol and the polymer polyol in the resin premix. Table 1 shows the evaluation results of the physical properties of the foam. In this example, the molding density (weight) of the mold foam was determined by checking the minimum filling weight (just pack) required for the mold foam to obtain a shape corresponding to the metal mold when both 0 part and 2 parts of carbon dioxide were used. 20 for the weight of
% Overfill (overpack). The properties (particularly density / hardness) suitable for a front cushion for automobiles in the case of 0 parts of carbon dioxide gas and for a rear cushion for automobiles in the case of 2 parts of carbon dioxide gas.

Example 2 A resin premix was molded and evaluated in the same manner as in Example 1 except that the types and amounts of polyoxyalkylene polyol and polymer polyol used in the resin premix were as shown in Table 1. Table 1 shows the results. In the case of 0 parts of carbon dioxide, it is used as a front cushion for automobiles,
In the case of 2 parts of carbon dioxide, physical properties (particularly density / hardness) suitable for a rear cushion for automobiles were obtained.

[0094]

[Table 1]

Example 3 Polyoxyalkylene polyol and polymer polyol as described in Table 1, 4.1 parts of water, 3.5 parts of a crosslinking agent, catalyst-10.
35 parts, catalyst-20.1 part, foam stabilizer-1 0.7 part, foam stabilizer-2 0.3 part, and polyoxyalkylene polyol G 1.0 part were mixed to prepare a resin premix. The resin premix and the polyisocyanate were mixed and discharged using a high-pressure foaming machine, and injected into a mold to prepare a molded foam molded article for foam evaluation. At this time, the resin premix injected into the mold and the NCO of polyisocyanate
The amount of the polyisocyanate was adjusted so that the index became 1.00.

Die: 400 × 400 × 100 mm aluminum test mold Die temperature: 56 to 60 ° C. Six minutes after injection of the molded foam, crushing was performed. . Crushing 50 molded articles
mm, then by passing through a 20 mm wide rotary roller.

The amount of carbon dioxide used was 0 parts (not used) and 2 parts based on 100 parts of polyoxyalkylene polyol and polymer polyol in the resin premix. Table 1 shows the evaluation results of the physical properties of the foam. In Examples, the molding density (weight) of the mold foam was fixed to 20% overfill (overpack) with respect to the minimum filling weight (just pack) in both cases of using 0 part and 2 parts of carbon dioxide gas. The properties (particularly density / hardness) suitable for a rear cushion for automobiles when the carbon dioxide gas content was 0 part and for the automobile seat back when the carbon dioxide gas content was 2 parts.

Example 4 A molded foam for foam evaluation was produced in the same manner as in Example 1 except that the resin premix of Example 3 was used and the NCO index and the overpack ratio were changed as shown in Table 2. Created. Only when the overpack ratio was 75%, pre-crushing was performed through a rotary roller having a width of 80 mm and then crushing was performed. The results are shown in Table 2. For example, if the overpack rate is about 20% at 0 parts of carbon dioxide, the overpack rate is about 75% at 0 parts of carbon dioxide.
%, Carbon dioxide 2
When the overpack ratio was about 20% in the portion, the physical properties (especially density / hardness) were suitable for an automobile seat back.

[0099]

[Table 2]

[0100]

The apparent density of a wide range of mold foams can be controlled by substantially changing only the physical foaming agent, so that a single line can be used for a plurality of brands, especially for a plurality of product groups. It can be easily manufactured.
As a result, parts required for one product can be manufactured in one cycle at a time even in automobile seats, beddings, and the like having different required shapes and performances for different parts of use. In addition, since the manufacturing order can be arbitrarily set in the order of the molds, each part can be manufactured in an order suitable for the shipping form of the product, particularly, packing at the time of shipping.

[Brief description of the drawings]

Fig. 1 Cold curing mold foam manufacturing process flow

FIG. 2 is a block diagram showing a configuration of a control device for a physical foaming agent.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Storage tank for polyisocyanate 2 Storage tank for resin premix 3 Metering pump for polyisocyanate 4 Metering pump for resin premix 5 Outbound piping for polyisocyanate 6 Outbound piping 7 Outbound piping for resin premix 8 Inbound piping 9 mixing head 10 physical foaming agent container 11 physical blowing agent for metering pump 12 physical blowing agent for liquid feed pipe 13 the line mixer 14 working zone 15 for curing oven 16 conveyor 17 release agent spray 18 product a _o ~a _n die

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Seijiro Sakai 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture F-term (reference) 4J034 CA04 CC03 DA01 DB04 DG02 DG14 DG23 DG27 DG28 DH02 DH05 DH06 HA01 HA07 HC12 HC61 HC71 HC73 NA01 NA02 NA03 NA06 PA05 QB01 QB15 QC01 QD03 RA10 RA12

Claims (5)

[Claims] 1. A method for producing a flexible polyurethane mold foam in which a polyol, a physical foaming agent and a polyisocyanate are used to foam in a mold, wherein the amount of the physical foaming agent is changed to make the flexible polyurethane mold foam appear. A method for producing a flexible polyurethane mold foam, comprising controlling the density. 2. A method for producing a flexible polyurethane mold foam, wherein the polyol according to claim 1 uses a polyol containing at least a polyoxyalkylene polyol. 3. The apparent density of a flexible polyurethane mold foam is controlled by controlling the amount of a physical foaming agent within a range of 3 parts by weight or less with respect to 100 parts by weight of a polyol. A method for producing a flexible polyurethane mold foam. 4. The apparent density of the flexible polyurethane molded foam is changed from 25 kg / m ³ to 45 kg / m ³ or 35 kg / m ³ to 6 by changing the discharge amount of the physical foaming agent into the mold.
4. The method for producing a flexible polyurethane molded foam according to claim 1, wherein the control is performed within a range of 5 kg / m ³ . 5. While changing the discharge amount of the physical foaming agent into the mold, at least one of the filling amount of the mixture of the polyol-containing resin premix and the polyisocyanate into the mold, and the NCO index of the mixture is determined. 4. The method according to claim 1, wherein the apparent density of the flexible polyurethane mold foam is controlled in the range of 30 kg / m ³ to 60 kg / m ³ and the hardness thereof is controlled in the range of 80 N / 314 cm ² to 500 N / 314 cm ² by changing. A method for producing a flexible polyurethane mold foam.